1. Field of the Invention
This invention relates to a pivotal armrest apparatus having a pivotal mechanism directly mounted on an anti-slip member. The pivotal mechanism automatically converts with the anti-slip member from irregular finger-movements into stress releasing movements, whereby RSI (Repetitive Strain Injury) can hardly be generated on the upper torso, nerves, and muscles. Also, the armrest makes the installation area minimum while it is detachable and used as a comfortable rest means for respite.
2. Description of the Related Art
Usually, while keyboard users or typists use standard layout keyboards for carrying out e.g. word processing, their fingers are held over the home row position of it with their forearms extending horizontally at the height of the keyboard and their palms in parallel with the surface of it. However, such a standard attitude causes user to be tensioned at the hand, palm, forearm, upper arm, and backs. While the QWERTY-layout is a standard for keyboard, a variety of modified keyboards have been proposed for alleviating the discomfort of muscles, and nerves of users. However, those modifications are not widely accepted because users favor psychologically for the QWERTY-layout. It is thus desired to develop a user-friendly keyboard which can successfully reduce RSI while its design remains not departing from the standard layout.
B1) Japanese Patent Laid-open No. (Heisei) 7-200121 describes a keyboard having a pointer and a tilting device for carrying out a pointing action with the hand remaining placed over the keyboard. In particular, the keyboard has an ergonomic arrangement comprising a left key bank and a right key bank separated at an angle of 20 to 36 degrees by an intermediate fan-like shaped sector which extends towards the front of the keyboard and has a track ball provided therein.
B2) U.S. Pat. No. 5,058,840 (Moss et al) describes a device which is slidably moved while supporting the forearm of a user from bottom.
B3) U.S. Pat. No. 5,398,896 (Terbrack) describes a device which is longitudinally moved slidably and pivotally moved about z-axis and has a linkage mechanism.
B4) U.S. Pat. No. 5,884,974 (Bergstern et al) describes a chair having armrests for supporting wrists which are adjustable in the height and pivotal about z-axis and also slidable longitudinally.
B5) Japanese Patent Laid-open No. (Heisei) 10-211794 describes an arm support for a keyboard-user having a pivot attached to the distal end of a linkage mechanism. The linkage is secured to a desk edge by clamp. The device has a joint (pivot) for allowing the forearm of a user to operate smoothly.
B6) U.S. Pat. No. 5,158,256 (Gross) describes a device moving longitudinally and having an adjustable means in the height of the wrist.
B7) U.S. Pat. No. 5,597,208 (Bonutti) describes a device for a chair having a transfer means mounted on the upper end of an L-shaped support pipe thereof for sliding movement horizontally and rotary movements about three rotational axes independently.
B8) U.S. Pat. No. 5,683,064 (Copeland) describes a manually positionable support device, especially for a work surface, keyboard support or similar support platform.
B9) U.S. Pat. No. 5,730,408 (McAllister, et al) describes a workstation support for a keyboard and a mouse.
B10) U.S. Pat. No. 5,810,301 (McGrath, et al) describes an adjustable, sturdy upper body support assembly for keyboard operators.
B11) U.S. Pat. No. 6,042,064 (Hong) describes a wrist support suitable for use by computer users to reduce RSI comprising a cushion mounted from an articulated strut so as to be rotatable about three axes.
However, all the above described technologies have the following disadvantages. A subjective inventor-side-evaluation (good, medium, low, poor, void) of each technology is shown at the last line as follows; support function of the arm ( ), pivot function ( ), detachable function ( ), anti-RSI function ( ), rest function ( ), size ( ), durability ( ) production cost ( ).
C1) The keyboard described in B1) supports mainly palms but fails to provide any means for lifting the forearm in the air. The static load which results from holding forearms over the keyboard for a long time can hardly be decreased fundamentally.
CB1: support (void), pivot (void), detach (void), RSI (void), rest (void), size ( ), durability ( ), cost ( )
C2) The device described in 840 (Moss et al) has a support movable so as to be: (a) freely pivotable about z-axis; (b) freely slidable along its length. A cradle is supported from the distal end of the support so as to be freely pivotable about a yaw-axis, and in addition to pitch in a fore and aft direction relative to the longitudinal axis of the cradle. The pitch motion is controlled in part by biasing springs which bias the cradle to a neutral pitch position when an out-of-balance force is removed from the cradle. The slide means consisting of a concentric cylindrical form is moved longitudinally, it suffers from a high sliding resistance. The arm support is secured to the top of a table with a vacuum suction plate at its base. The support is used on the outside area of the base, and constantly received a gravity-moment created by the arm to the overturning direction. The required space for the slide movement is large above the top of the table, increasing the overall dimensions of the support. The cradle is supported by biasing springs, the forearm holds to stay substantially at a constant angular attitude, and this causes RSI during a long-term operation. The springs also cause fingers to drift slightly from one location to another, where by the accurate positioning of fingers needs its nerves and muscles being tensioned continuously.
CB2: support (medium), pivot (void), detach (low), RSI (low), rest (void), size (poor), durability (poor), cost (poor)
C3) The device described in 896 (Terbrack) comprises an elongate guide-track and a pair of support assemblies which are adapted to support user""s palms adequately. Each of the support assemblies comprises a carriage slidably engaged to the guide-track and a linkage pivotally connected to the carriage. The pivotal connection and the slidable engagement of the carriage facilitates dynamic lateral and longitudinal movement of the support and hence the user""s hands relative to the guide track. A pin in the linkage is hardly increased in the diameter, the strength is hardly enough to. The height control along z-axis is hardly considered, the forearm is hardly free from RSI. The rotatable linkage causes fingers to drift slightly from one location to another, the supported arm needs its nerves and muscles being tensioned continuously.
CB3: support (poor), pivot (void), detach (void), RSI (poor), rest (void), size (poor), durability (poor), cost (poor).
C4) The arm support described in 974 (Bergstern) is installed at a desk edge with clamp, and this causes a drawback of the drawer. The support occupies a broad surface of the desk. The sliding shaft of the support is constructed by a point contact, it receives concentrated loads and if worse, will bend down. The support once installed may hardly be removed, and includes a large number of components thus increasing the overall cost.
CB4: support (low), pivot (void), detach (void), RSI (poor), rest (void), size (poor), durability (poor), cost (poor)
C5) The arm support described in B5) has a similar drawback to 974 (Bergston). A linkage to the support occupies a bulky space of the desk, or the clamp shape of the linkage varies very widely matching to the edge shapes of the desks to be attached to. The clamp has a weak strength and impairs the surface of the desk. After a long-term use, the pivot may be impaired slippery thus making the support unstable. In case of mass-production, the compatibility of the pivot may hardly be guaranteed. The support is pivotally connected to the distal end of the linkage constantly receiving a gravity-moment created by the arm to the overturning direction, and causing fingers to slightly drift from one location to another, then the supported arm needs its nerves and muscles being tensioned continuously.
CB5: support (medium), pivot (medium), detach (poor), RSI (low), rest (void), size (low), durability (low), cost (medium).
C6) The device described in 256 (Gross) supports mainly the palm rather than the forearm, and the platform is located in the front side of a desk. The structure of the arm support is very intricate, and a detachable step of it is also very intricate. A movement of the wrist is very limited, and the platform disturbs using the center drawer of the desk.
CB6: support (poor), pivot (void), detach(void), RSI (poor), rest (poor), size (poor), durability (poor), cost (poor)
C7) The device described in 208 (Bonutti) has a slide member and three pivot joints. Three pivot joints occupy very bulky space, and the clamp of the base to a desk is obsolete, many projections of the device collide with the chair or impair the body of a user or his clothes.
CB7: support (medium), pivot (medium), detach (poor), RSI (low), rest (low), size (poor), durability (poor), cost (poor)
C8) The device described in 064 (Copeland) is installed to the underside of a desk. Its installation deteriorates the physical strength of the desk, and disturbs the use of a drawer. A detachable step of it is very intricate.
CB8: support (poor), pivot (void), detach (void), RSI (poor), rest (void), size (poor), durability (poor), cost (poor)
C9) The device described in 408 (McAllister) has an arm to a mouse pad, and a mouse support table is adjustably attached to it via an off-center rotational joint. The arm is broken down when receiving the overall weight of the user, and the structure of the arm is very intricate.
CB9: support (void), pivot (low), detach (void), RSI (poor), rest (void), size (low), durability (low), cost (medium)
C10) The system described in 301 (McGrath) has an adjustable, upper body support assembly for keyboard users including a pair of adjustable armrests mounted on a rigid frame. The assembly is positioned adjacent and partially underneath a piece of furniture. The assembly also includes a support frame and an upper body support apparatus. The support apparatus is movably engaged with the frame to permit the apparatus to be moved underneath a piece of furniture when not in use. The support system is very large, required a huge installation space, scrapping the old desk, wasting resources. The armrest has no pivot function, and its cost is very high.
CB10: support (poor), pivot (void), detach (poor), RSI (poor), rest (low), size (poor), durability (low), cost (poor)
C11) The device described in 064 (Hong) has a wrist support to reduce RSI comprising a cushion mounted from an articulated strut so as to be movable about three axes whereby it may yaw, pitch and roll relative to the strut, and a spring to bias the cushion to a neutral pitch and roll position. But the structure based on three axes requires a relatively large complex one, the size of the support under the cushion is large. The articulated strut is a kind of linkage constantly receiving a gravity-moment created by the arm to overturning direction, and causing fingers to slightly drift from one location to another, the supported arm needs its nerves and muscles being tensioned continuously.
CB11: support (medium), pivot (medium), detach (poor), RSI (medium), rest (low), size (low), durability (low), cost (low).
C12) In a data entry operation for 3-DCAD software, its user has to hold and operate a mouse continuously for irregular and complicated motion while its forearm remaining lifted up over two or four hours and may feel fatigue or pain on his arm. Some users for advanced CAD software claim that they feel a kind of fatigue just when watching the mouse. With its personal computer and keyboard placed together on a desk, the space for operating the mouse on it should be saved as small as possible. We, the inventors, found through a series of mouse operating actions that the controlling of the mouse is easy by conducting a combination of the translation motion and the angular rotations when the forearm remains held not to move linearly in x-y directions but rotatable for shifting its angular attitude in a system, the wrist is floating freely in all directions.
In summarizing the description in C1 to C12, the RSI problems ever since type-writers and computers were introduced are now focused and their solutions are attempted particularly by manufacturers, distributors, and end users with lots of failures due to multiple reciprocal requests existing in the problems. So far, no convenient devices are provided for fundamentally eliminating the above problems. As the fingers or wrist of a user is generally fixed within a limited range of the space, its movable range is allowed no large spatial freedom by the initial given conditions. Also, as the conventional devices of the prior art are designed for supporting pain-portions of the hand near the wrist, its mechanism is limited by pain-conditions thus narrowing motion of wrists. This will be disadvantageous particularly to the long-acting user.
For example, when user operates an entry means of a computer at a same location and at a same attitude, it may suffer from RSI on his muscles, chords, and nerves. Even when translation motion and rotating movements are permitted by the action of a linkage, the operating position of the hand is only shifted from one location to another on the same horizontal plane, and no attitude changes are derived from action of the linkage. For preventing from drifting largely from their initial operating position, the arms of user have to be tensioned more or less on the upper torso. Accordingly, RSIs remain unsolved. The conventional mechanism for permitting the rotating movements in three degrees of freedom (DOF) is based on the armrest combined with a rotary mechanism for having three independent axes as described in the paragraphs B7 and B11 and its structure becomes very bulky and complex, hence making the installation on the desk difficult.
C13) As a conventional armrest comprises a device for supporting the forearm and a transfer means which are separately provided and assembled not integrally, it needs relatively wider area for installation. Also, as typically described in the paragraph B10, a dedicated set of a desk and a chair for operating a computer is commercially available. When such a new set is obtained, the existing desk is no more needed and may be wasted leading to losses of resources. The dedicated set of desk is unfavorable for use in different applications. The desk once used with a conventional armrest exhibits undulations or dents in its upper or side surface and maybe found of no use. This will decline the efficiency of utilization of a room where the desk is installed and force the owner of the room to charge a higher fee to a tenant.
The inventors have pointed out that a mechanism for physically supporting the forearm of user at its center-of-gravity (while the hand remain substantially floating in the air) is much friendly to movements of the hand. The present invention is developed in view of the above aspects and its object is to provide a pivotal armrest apparatus which is comfortable for operating a keyboard or a mouse, and will invite very little RSI-problems when used for a long period of time.
An advantage of the present invention is to provide an armrest in which a pivotal mechanism mounted on an anti-slip member is introduced to provide a soft-rigidity for the pivot motion, and this invites a simple structure, a very comfortable controllability in use, and very little RSI-problems.
For the achievement of the object, an armrest apparatus according to the present invention is comprising:
a base member detachably mounted on the surface of a table or desk;
a cradle means supporting an elbow-side portion of a forearm from the wrist; and said base member and said cradle means further including
a pivotal mechanism formed by directly connecting to each other; and
said pivotal mechanism including a pivotably curved-surface of a predetermined shape, wherein while said forearm is supported by said cradle means, the location and the attitude of said forearm can be controlled in any desired movement by said pivotal mechanism.
For another achievement of the object, an armrest apparatus according to the present invention is provided comprising:
a cradle means supporting an elbow-side portion of a forearm from the wrist;
a pivotal mechanism formed by directly mounting said cradle means on the surface of a table or desk;
an anti-slip member interposed between said cradle means and said surface of a desk; and
said pivotal mechanism including a pivotably curved-surface of a predetermined shape, wherein while said forearm is supported by said cradle means, the location and the attitude of said forearm can be controlled in any desired movement by said pivotal mechanism.
According to the present invention, a method for installing an armrest apparatus on a surface of a desk, said armrest apparatus including a base member detachably mounted on the surface of the desk and a cradle means supporting an elbow-side portion of a forearm from the wrist, the steps of the method comprising:
forming a pivotal mechanism by directly connecting said base member and said cradle means to each other; and,
mounting said base member on said surface of the desk at a desired location.
Our invention will be explained in greater detail in relation to preferred embodiments thereof, as shown in the accompanying drawings.